QuTiP: Quantum Toolbox in Python

1–30 of 973

Welcome to the QuTiP users Group. To join, just post a message!

Note this group is for help in installing or using the toolkit, or general idea for the project.

For issues and ideas about, and contributions to, the QuTiP code go to the QuTiP GitHub

If you need help using QuTiP please look through the old posts before submitting a new one.

0 selected

ANUSHREE DEY, Simon Cross2

Jan 21

import cursor in qutip

Hi Anushree, Could you give a short example of the code that is failing? I have no idea what "

unread,

import cursor in qutip

Hi Anushree, Could you give a short example of the code that is failing? I have no idea what "

Jan 21

Luciano Ricco, Neill Lambert3

Jan 21

Spectrum function using fermionic operators from Jordan-Wigner transformation

Hi Neill, Thank you very much for your answer and sorry for my late reply. I will try to use the

unread,

Spectrum function using fermionic operators from Jordan-Wigner transformation

Hi Neill, Thank you very much for your answer and sorry for my late reply. I will try to use the

Jan 21

Pradip Laha

Jan 21

Issues with logarithmic_negativity function

Hi all, Still new to QuTiP. Trying to use the logarithmic_negativity function (a simple code is

unread,

Issues with logarithmic_negativity function

Hi all, Still new to QuTiP. Trying to use the logarithmic_negativity function (a simple code is

Jan 21

Marco Pereira, … Simon Cross7

Jan 20

How to represent this coherence in 4D

Simon, Now I noticed that you asked me to post a link. I am new to discord and googlegroups. I am not

unread,

How to represent this coherence in 4D

Simon, Now I noticed that you asked me to post a link. I am new to discord and googlegroups. I am not

Jan 20

MS, Simon Cross3

Jan 20

Import Error

Hi MS, You're encountering this issue https://github.com/qutip/qutip/issues/1766 which results

unread,

Import Error

Hi MS, You're encountering this issue https://github.com/qutip/qutip/issues/1766 which results

Jan 20

Simon Cross

Jan 20

First QuTiP Community Call of 2022

Greetings, We'd like to welcome you to join us at the first QuTiP community call of 2022! QuTiP

unread,

First QuTiP Community Call of 2022

Greetings, We'd like to welcome you to join us at the first QuTiP community call of 2022! QuTiP

Jan 20

Azmat Habibullah, … Ravi Roy11

Jan 18

Help computing Berry phase, connection and curvature

Hello Saumya . This thread has really helped me in understanding the concepts beautifully. May I ask

unread,

Help computing Berry phase, connection and curvature

Hello Saumya . This thread has really helped me in understanding the concepts beautifully. May I ask

Jan 18

Nicolas Gevers, Simon Cross2

Jan 5

power-gmres failed to find solution in 1000 iterations.

Hi Nicolas, Is this the same bug report as https://github.com/qutip/qutip/issues/1750? If so,

unread,

power-gmres failed to find solution in 1000 iterations.

Hi Nicolas, Is this the same bug report as https://github.com/qutip/qutip/issues/1750? If so,

Jan 5

Najme*, Simon Cross2

Jan 3

derive the steady-state master equation as a function of dissipation rate

Hi Najmeh, I opened your .ipynb briefly. It looks like you are calling `steadystate(H, c_ops[i])`.

unread,

derive the steady-state master equation as a function of dissipation rate

Hi Najmeh, I opened your .ipynb briefly. It looks like you are calling `steadystate(H, c_ops[i])`.

Jan 3

Behrooz Rezaei, Simon Cross2

12/29/21

Zak phase calculations in 1D photonic crystal

Hi Behrooz, Do you have a reference you are following for the Zak phase calculations? Would you like

unread,

Zak phase calculations in 1D photonic crystal

Hi Behrooz, Do you have a reference you are following for the Zak phase calculations? Would you like

12/29/21

Jonah Peter, … Neill Lambert8

12/21/21

How to simulate a non-Hermitian Hamiltonian?

hi Jonah, Just wanted to follow up on this. Is the proper way to simulate a non-Hermitian Hamiltonian

unread,

How to simulate a non-Hermitian Hamiltonian?

hi Jonah, Just wanted to follow up on this. Is the proper way to simulate a non-Hermitian Hamiltonian

12/21/21

hamids...@gmail.com, shahnawa...@gmail.com2

12/21/21

Problem: Estimate the process fidelity with quantum process tomography

Hi, I could help you out here. Here is a notebook that I am working on related to process tomography:

unread,

Problem: Estimate the process fidelity with quantum process tomography

Hi, I could help you out here. Here is a notebook that I am working on related to process tomography:

12/21/21

Mehdi Aslani, j794...@uwaterloo.ca3

12/13/21

Passing a time-dependent operator to mesolve's e_ops argument

Thanks, the first solution worked On Monday, December 13, 2021 at 6:16:42 AM UTC+3:30 j794...@

unread,

Passing a time-dependent operator to mesolve's e_ops argument

Thanks, the first solution worked On Monday, December 13, 2021 at 6:16:42 AM UTC+3:30 j794...@

12/13/21

ahmad.j...@gmail.com, … j794...@uwaterloo.ca4

12/8/21

How to obtain the actual time evolution operators using QuTiP solvers?

Hi all, The simplest way to retrieve a time-evolution operator is using the 'propagator'

unread,

How to obtain the actual time evolution operators using QuTiP solvers?

Hi all, The simplest way to retrieve a time-evolution operator is using the 'propagator'

12/8/21

Mirko Rossini, Simon Cross2

12/6/21

Quantum Discord in QuTiP

Hi Mirko, I assume you are referring to https://github.com/qutip/qutip/issues/1450. No one has taken

unread,

Quantum Discord in QuTiP

Hi Mirko, I assume you are referring to https://github.com/qutip/qutip/issues/1450. No one has taken

12/6/21

mahmoud mohammadi

11/25/21

help

Hello, dear members of the group I want to get the Thermal density matrix for a cavity-atomic system

unread,

help

Hello, dear members of the group I want to get the Thermal density matrix for a cavity-atomic system

11/25/21

j794...@uwaterloo.ca, … Asier Galicia21

11/18/21

The use of collapse operator for solving time-evolution operator

Hey, I posted an issue in the QuTiP repository summarizing what was discussed here. I hope it is

unread,

The use of collapse operator for solving time-evolution operator

Hey, I posted an issue in the QuTiP repository summarizing what was discussed here. I hope it is

11/18/21

Leeseok Kim, Simon Cross5

11/16/21

Customizing the cost function for GRAPE algorithm

Hi Leeseok, I think for GRAPE in QuTiP you would need to implement a custom FidelityComputer (see

unread,

Customizing the cost function for GRAPE algorithm

Hi Leeseok, I think for GRAPE in QuTiP you would need to implement a custom FidelityComputer (see

11/16/21

Leeseok Kim, Asier Galicia2

11/15/21

Landau-Zener-Stuckelberg inteferometry

Hi, thanks for letting us know that this notebook was behaving unexpectedly. It turns out it was aa

unread,

Landau-Zener-Stuckelberg inteferometry

Hi, thanks for letting us know that this notebook was behaving unexpectedly. It turns out it was aa

11/15/21

Leeseok Kim, Simon Cross2

11/15/21

few questions on pulses options for optimize_pulse function

Hi Leeseok, You can find the documentation for optimize_pulse at https://qutip.org/docs/latest/apidoc

unread,

few questions on pulses options for optimize_pulse function

Hi Leeseok, You can find the documentation for optimize_pulse at https://qutip.org/docs/latest/apidoc

11/15/21

Burak Gürlek, Simon Cross2

11/15/21

Problem with Wigner fuction for large excitation numbers

Hi Burak, When I tried your example I got an overflow warning before I receiving the nan results:

unread,

Problem with Wigner fuction for large excitation numbers

Hi Burak, When I tried your example I got an overflow warning before I receiving the nan results:

11/15/21

Najme*, … Simon Cross5

11/15/21

Extracting final density matrix from mesolve

Hi Harman, > can we extract density matrix if we had specified the expectation operator in mesolve

unread,

Extracting final density matrix from mesolve

Hi Harman, > can we extract density matrix if we had specified the expectation operator in mesolve

11/15/21

Joan Agusti, Simon Cross3

11/15/21

Solving time-dependent master equation with different jump operators

Hi Joan, > a_t = QobjEvo([a, f(t)]) I just realised that I followed your pseudocode notation here

unread,

Solving time-dependent master equation with different jump operators

Hi Joan, > a_t = QobjEvo([a, f(t)]) I just realised that I followed your pseudocode notation here

11/15/21

hamids...@gmail.com, Simon Cross3

11/9/21

Quantum process or state tomography of three-qubit gate which generate the GHZ-stae

Hi Simon, I would like to thank you for your reply, for my case, i want to measure the quantum

unread,

Quantum process or state tomography of three-qubit gate which generate the GHZ-stae

Hi Simon, I would like to thank you for your reply, for my case, i want to measure the quantum

11/9/21

rupay...@gmail.com, Simon Cross2

11/8/21

Exception: The size of the m_ops does not fit the intial state

Hello, The issue is that m_ops is supposed to be a list -- ie m_ops=[x]. Yours sincerely, Simon Cross

unread,

Exception: The size of the m_ops does not fit the intial state

Hello, The issue is that m_ops is supposed to be a list -- ie m_ops=[x]. Yours sincerely, Simon Cross

11/8/21

ham as, … Saumya biswas5

11/5/21

Problem in time dependent hamiltonian

Thanks Saumya biswas, yes i familiar with (RWA), but this hamiltonian is in the RWA, can not be

unread,

Problem in time dependent hamiltonian

Thanks Saumya biswas, yes i familiar with (RWA), but this hamiltonian is in the RWA, can not be

11/5/21

ANUSHREE DEY, … Neill Lambert7

10/31/21

error coming during solving steady state density matrix

Dear Neil, It is indeed blissful to hear from you about the possible reason for the problem.

unread,

error coming during solving steady state density matrix

Dear Neil, It is indeed blissful to hear from you about the possible reason for the problem.

10/31/21

Joan Arrow, Gaurav Saxena2

10/27/21

Is it possible to modify the source code of a qutip object like Bloch?

Hey Joan, You can easily do something like this: b= Bloch( figsize=[10,10]) b.xlabel = ['$\\left|

unread,

Is it possible to modify the source code of a qutip object like Bloch?

Hey Joan, You can easily do something like this: b= Bloch( figsize=[10,10]) b.xlabel = ['$\\left|

10/27/21

Real Solace, Andrew M. C. Dawes3

10/27/21

Hbar in qutip

Thanks, I've re-scaled and they look as expected so far. I will post more details once I decide

unread,

Hbar in qutip

Thanks, I've re-scaled and they look as expected so far. I will post more details once I decide

10/27/21

Chris Nill, … Saumya biswas3

10/26/21

could not display_lattice of a standard lattice1d

Hi. Chris. Sorry, we did not get any questions for qutip.lattice in a while. Could you please check

unread,

could not display_lattice of a standard lattice1d

Hi. Chris. Sorry, we did not get any questions for qutip.lattice in a while. Could you please check

10/26/21